A new biochemical index was used to assess larval fish nutritional condition during a. survey cruise in the Bay of Biscay in early June 1993. This period corresponds to the breeding season of the European anchovy (Engraulis encrasicolus L.). The analysis of samples taken at grid points indicated a clear spatial pattern in nutritional condition, which increased from the middle shelf to the shelf edge. A relatively large fraction of the larval population proved to be in poor condition. Strong winds with speeds of 20-30 knots occurred during 3 d after the first survey and affected the vertical hydrological structure. During a subsequent survey, samples taken at approximately the same locations showed that anchovy larvae in all areas were in very poor condition. These results support the notion that some environmental stability is required for good feeding conditions. Strong winds are not uncommon in the Bay of Biscay and their potential effects on anchovy recruitment variability are discussed.